diff --git a/Source/Scene/CreditDisplay.js b/Source/Scene/CreditDisplay.js
index d451bec6d9c5..07ab6a638db6 100644
--- a/Source/Scene/CreditDisplay.js
+++ b/Source/Scene/CreditDisplay.js
@@ -516,7 +516,7 @@ function getDefaultCredit() {
 
     // When hosting in a WebView, the base URL scheme is file:// or ms-appx-web://
     // which is stripped out from the Credit's <img> tag; use the full path instead
-    if (!logo.startsWith("http://") && !logo.startsWith("https://")) {
+    if (logo.indexOf("http://") !== 0 && logo.indexOf("https://") !== 0) {
       var logoUrl = new Uri(logo);
       logo = logoUrl.getPath();
     }